Clindamycin and primaquine are drugs that have been used extensively in humans. Clindamycin is an lincosamide antibiotic active against a variety of bacteria including aerobic gram positive cocci, anaerobic gram negative bacilli, anaerobic gram positive nonspore-forming bacilli, and anaerobic and microaerophilic cocci. The preparation of clindamycin is given by Magerlein, et al., in Anti-microbial Agents and Chemotherapy, 727 (1966). Clindamycin also has activity against malarial parasites although the exact effect on plasmodia is not known. The drug is rapidly and virtually completely absorbed after oral dosage and distributes well into body fluids and tissues. Primaquine is a potent anti-malarial agent now used mainly for radical cure of vivax malaria. The preparation of primaquine is given by Elderfield, et al., in Journal of the American Chemical Society, 4816 (1955). The drug is rapidly absorbed after oral dosage and has extensive tissue distribution.
An estimated one to one and one-half million people in the United States are infected with a human retrovirus, the human immunodeficiency virus type I, HIV-1, which is the etiological agent of acquired immunodeficiency syndrome, AIDS, Norman, C., Science, 661-662 (1986). Of those infected, an estimated two hundred and fifty thousands people will develop AIDS in the next five years, Curran, J.W., et al., Science, 1352-1357 (1985). Pneumocystis carinii pneumonia is the most common life threatening infection in patients with aids. The infection occurs at least once in as many as eighty percent of AIDS patients and about one third of the total number of episodes of pneumocystis carinii pneumonia are fatal. Fewer than one half of the AIDS patients treated with conventional drugs, either trimethoprim/sulfamethoxazole or pentamidine, are able to complete a full course of therapy because a majority of these patients develop one or more serious adverse reactions such as severe rash, neutropenia, thrombocytopenia, anemia, liver disfunction, renal failure or disturbances in serum glucose, calcium or sodium levels.